2011 INFINITI QX56 ABS

P0500 VSSEC-357
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O4. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to
EC-357, "Diagnosis Procedure".
NO >> INSPECTION END
4.PERFORM COMPONENT FUNCTION CHECK
WITH GST
Perform Component Function Check. Refer to EC-357, "
Component Function Check".
Use Component Function Check to check the overall func tion of the vehicle speed signal circuit. During this
check, a 1st trip DTC might not be confirmed.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-357, "
Diagnosis Procedure".
Component Function CheckINFOID:0000000006217859
1.PERFORM COMPONENT FUNCTION CHECK
WITH GST
1. Lift up drive wheels.
2. Start engine.
3. Read vehicle speed signal in Service $01 with GST. The vehicle speed signal on GST should be able to ex ceed 10 km/h (6 MPH) when rotating wheels with
suitable gear position.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Go to EC-357, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000006217860
1.CHECK DTC WITH “ABS ACTUATOR AND ELECTRIC UNIT (CONTROL UNIT)”
Refer to BRC-40, "
CONSULT-III Function".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace malfunctioning part.
2.CHECK DTC WITH “COMBINATION METER”
Refer to MWI-30, "
CONSULT-III Function".
>> INSPECTION END
B/FUEL SCHDL 5.5 - 31.8 msec
Selector lever Except P or N position
PW/ST SIGNAL OFF
Revision: 2010 May2011 QX56

P0643 SENSOR POWER SUPPLYEC-381
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P0643 SENSOR POWER SUPPLY
DTC LogicINFOID:0000000006217882
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confi rm that battery voltage is 8 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for 1 second.
2. Check DTC.
Is DTC detected?
YES >> Go to EC-381, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217883
1.CHECK ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between APP sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 6.
NO >> GO TO 2.
2.CHECK SENSOR POWER SUPPLY CIRCUIT
Check harness for short to power and short to ground, between the following terminals.
DTC No.Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P0643 SENSOR POWER/CIRC
(Sensor power su
pply circuit
short) ECM detects that the voltage of
power source for sensor is ex-
cessively low or high.  Harness or connectors
(Accelerator pedal position sensor 1 circuit is shorted.)
[Camshaft position sensor (bank 2) circuit is shorted.]
[Manifold absolute pressure (MAP) sensor circuit is
shorted.]
(Throttle position sensor circuit is shorted.)
 Accelerator pedal position sensor 1
 Camshaft position sensor (bank 2)
 Manifold absolute pressure (MAP) sensor
 Throttle position sensor
APP sensor Ground Voltage (V)
Connector Terminal
E110 (Without ICC) 2 Ground Approx. 5
E67 (With ICC) 12
Revision: 2010 May2011 QX56

EC-382
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P0643 SENSOR POWER SUPPLY
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair short to ground or short to power in harness or connectors.
3.CHECK COMPONENTS
Check the following.
 Camshaft position sensor (bank 2) (Refer to EC-306, "
Component Inspection (Camshaft Position Sensor)".)
 Manifold absolute pressure (MAP) sensor (Refer to EC-208, "
Component Inspection (MAP Sensor)".)
Is the inspection result normal?
YES >> GO TO 4.
NO >> Replace malfunctioning component.
4.CHECK THROTTLE POSITION SENSOR
Refer to EC-220, "
Component Inspection (Throttle Position Sensor)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 5.
5.REPLACE ELECTRIC THROTTLE CONTROL ACTUATOR
Replace electric throttle control actuator. Refer to EM-30, "
Removal and Installation".
>> INSPECTION END
6.CHECK ACCELERATOR PEDAL POSITION SENSOR
Refer to EC-470, "
Component Inspection (Accelerator Pedal Position Sensor)".
Is the inspection result normal?
YES >> GO TO 8.
NO >> GO TO 7.
7.REPLACE ACCELERATOR PEDAL ASSEMBLY
Replace accelerator pedal assembly. Refer to ACC-3, "
MODELS WITHOUT DISTANCE CONTROL ASSIST
SYSTEM : Removal and Installation" (Without distance control assist system) or ACC-4, "MODELS WITH
DISTANCE CONTROL ASSIST SYSTEM : Removal and Installation" (With distance control assist system).
>> INSPECTION END
8.CHECK INTERMITTENT INCIDENT
Refer to GI-40, "
Intermittent Incident".
>> INSPECTION END
ECM Sensor
Connector Terminal Name Connector Terminal
F 111 81 Electric throttle control actuator F66 2
83 Camshaft position sensor (bank 2) F83 1
85 Manifold absolute pressure (MAP) sensor F65 1
E80 137 APP sensor 1 (Without ICC) E110 2
137 APP sensor 1 (With ICC) E67 12
Revision: 2010 May2011 QX56

P1212 TCS COMMUNICATION LINEEC-399
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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P1212 TCS COMMUNICATION LINE
DescriptionINFOID:0000000006217906
This CAN communication line is used to control the
smooth engine operation during the TCS operation. Pulse
signals are exchanged between ECM and “ABS actuator and electric unit (control unit)”.
Be sure to erase the malfunction information such as DTC not only fo r “ABS actuator and electric unit
(control unit)” but also for ECM after TCS related repair.
DTC LogicINFOID:0000000006217907
DTC DETECTION LOGIC
NOTE:
 If DTC P1212 is displayed with DTC UXXXX, perform the trouble diagnosis for DTC UXXXX.
 If DTC P1212 is displayed with DTC P0607, perform the trouble diagnosis for DTC P0607.
Freeze frame data is not stored in the ECM for this self-diagnosis.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is 10.5 V or more at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-399, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217908
Perform the trouble diagnosis for TCS. Refer to BRC-60, "Work Flow".
NOTE:
If DTC P1212 is displayed with DTC UXXXX and/or P0607, perform the following trouble diagnosis.
 Trouble diagnosis for DTC UXXXX Refer to EC-98, "
DTC Index".
 Trouble diagnosis for DTC P0607 Refer to EC-378, "
DTC Logic".
DTC No.Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1212 TCS/CIRC
(TCS communication line) ECM cannot receive the information from
“ABS actuator and electric unit (control
unit)” continuously.  Harness or connectors
(The CAN communication line is open or short-
ed.)
 ABS actuator and electric unit (control unit)
 Dead (Weak) battery
Revision: 2010 May2011 QX56

P1574 ASCD VEHICLE SPEED SENSOREC-447
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P1574 ASCD VEHICLE SPEED SENSOR
DescriptionINFOID:0000000006288349
The ECM receives two vehicle speed signals by the CAN
communication line. One is sent from “combination
meter”, and the other is from TCM (Transmission cont rol module). The ECM uses these signals for ASCD con-
trol. Refer to EC-48, "
AUTOMATIC SPEED CONTROL DEVICE (ASCD) : System Description" for ASCD func-
tions.
DTC LogicINFOID:0000000006288350
DTC DETECTION LOGIC
NOTE:
 If DTC P1574 is displayed with DTC UXXXX, perform the trouble diagnosis for DTC UXXXX.
 If DTC P1574 is displayed with DTC P0500, perform the trouble diagnosis for DTC P0500. Refer to
EC-356, "
DTC Logic".
 If DTC P1574 is displayed with DTC P0605, perform the trouble diagnosis for DTC P0605. Refer to
EC-376, "
DTC Logic".
 If DTC P1574 is displayed with DTC P0607, perform the trouble diagnosis for DTC P0607. Refer to
EC-378, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine (VDC switch OFF).
2. Drive the vehicle at more than 40 km/h (25 MPH). CAUTION:
Always drive vehicle at a safe speed.
NOTE:
This procedure may be conducted with the drive wheel s lifted in the shop or by driving the vehicle.
If a road test is expected to be easier , it is unnecessary to lift the vehicle.
3. Check DTC.
Is DTC detected?
YES >> Proceed to EC-449, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288351
1.CHECK DTC WITH TCM
Check DTC with TCM. Refer to TM-61, "
CONSULT-III Function (TRANSMISSION)".
Is the inspection result normal?
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1574 ASCD VHL SPD SEN
(ASCD vehicle speed sensor) ECM detects a difference between two vehicle
speed signals is out of the specified range.  Harness or connectors
(The CAN communication line is open
or shorted.)
 Combination meter
 ABS actuator and elec tric unit (control
unit)
 Wheel sensor
TCM
ECM
Revision: 2010 May2011 QX56

EC-448
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1574 ASCD VEHICL
E SPEED SENSOR
YES >> GO TO 2.
NO >> Perform Diagnosis Procedure corresponding to the DTC indicated.
2.CHECK DTC WITH “ABS ACTUATOR A ND ELECTRIC UNIT (CONTROL UNIT)”
Refer to BRC-40, "
CONSULT-III Function".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Perform Diagnosis Procedure corresponding to the DTC indicated.
3.CHECK DTC WITH “COMBINATION METER”
Refer to MWI-30, "
CONSULT-III Function".
>> INSPECTION END
Revision: 2010 May2011 QX56

P1574 ICC VEHICLE SPEED SENSOR
EC-449
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P1574 ICC VEHICLE SPEED SENSOR
DescriptionINFOID:0000000006288352
The ECM receives two vehicle speed signals by the CAN
communication line. One is sent from “combination
meter”, and the other is from TCM (Transmission cont rol module). The ECM uses these signals for ICC con-
trol. Refer to CCS-12, "
System Description" for ICC functions.
DTC LogicINFOID:0000000006288353
DTC DETECTION LOGIC
NOTE:
If DTC P1574 is displayed with DTC UXXXX, first perform the tr ouble diagnosis for DTC UXXXX.
 If DTC P1574 is displayed with DT C P0500, first perform the trouble diagnosis for DTC P0500. Refer
to EC-356, "
DTC Logic".
 If DTC P1574 is displayed with DT C P0605, first perform the trouble diagnosis for DTC P0605. Refer
to EC-376, "
DTC Logic".
 If DTC P1574 is displayed with DT C P0607, first perform the trouble diagnosis for DTC P0607. Refer
to EC-378, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine (VDC switch OFF).
2. Drive the vehicle at more than 40 km/h (25 MPH). CAUTION:
Always drive vehicle at a safe speed.
NOTE:
This procedure may be conducted with the drive wheel s lifted in the shop or by driving the vehicle.
If a road test is expected to be easier , it is unnecessary to lift the vehicle.
3. Check DTC.
Is DTC detected?
YES >> Proceed to EC-449, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006288354
1.CHECK DTC WITH TCM
Check DTC with TCM. Refer to TM-61, "
CONSULT-III Function (TRANSMISSION)".
Is the inspection result normal?
YES >> GO TO 2.
DTC No. Trouble diagnosis name
(Trouble diagnosis content) DTC detecting condition Possible cause
P1574 ASCD VHL SPD SEN
(ICC vehicle speed sensor) ECM detects a difference between two vehicle
speed signals is out of the specified range.  Harness or connectors
(The CAN communication line is open or
shorted.)
 Combination meter
 ABS actuator and electric unit (control unit)
 Wheel sensor
TCM
ECM
Revision: 2010 May2011 QX56

EC-450
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1574 ICC VEHICLE SPEED SENSOR
NO >> Perform Diagnosis Procedure corresponding to the DTC indicated.
2.CHECK DTC WITH “ABS ACTUATOR A
ND ELECTRIC UNIT (CONTROL UNIT)”
Refer to BRC-40, "
CONSULT-III Function".
Is the inspection result normal?
YES >> GO TO 3.
NO >> Perform Diagnosis Procedure corresponding to the DTC indicated.
3.CHECK DTC WITH “COMBINATION METER”
Check combination meter function.
Refer to MWI-30, "
CONSULT-III Function".
>> INSPECTION END
Revision: 2010 May2011 QX56